LITTLE ROCK (AP) — A man sentenced to die for the slayings of an Arkansas gun dealer and his family is to argue before a federal judge on Friday for a new sentencing hearing on grounds that the results of an invalid test were put before the jury.

Danny Lee, 45, of Yukon, Okla. was convicted in the 1996 slayings of William Mueller, his wife, Nancy, and young daughter, Sarah. Lee and Chevie Kehoe, who also robbed the family, were trying to establish a white supremacist nation in the Pacific Northwest.

Prosecutors say the Muellers were shocked with stun guns and Kehoe and Lee put plastic trash bags over their heads, which caused the victims to suffocate. The bodies were found in Illinois Bayou in Russellville. Lee and Kehoe stole firearms and $50,000 in cash from the Muellers.

Lee argues in court papers that jurors considered the results of a psychological test that showed him to be a psychopath who would be a continued threat, even while jailed. Lee claims the test has since been discredited and that he is the only person on federal death row whose sentencing included use of the test.

Lee claims in court papers that his trial attorney was “ineffective for failing to adequately challenge aggravating evidence at sentencing.” Lee’s current attorney claims there was no solid evidence that Lee is a psychopath or that he posed a danger but the trial attorney didn’t object to the information being introduced before the jury.

The filing quotes the trial judge, U.S. District Judge G. Thomas Eisele as saying it was “very questionable whether the jury would have given Defendant Lee the death penalty.”

Federal prosecutors say Lee has failed to show there are ‘extraordinary circumstance” that merit reopening the sentencing phase of his trial.